Organic electroluminescent device, manufacturing method therefor, and electronic devices therewith

ABSTRACT

A method for manufacturing an organic EL device comprising: coating a composition including an organic EL material on a plurality of electrodes to form an organic EL layer on each electrode; defining an effectively optical area in which the plurality of electrodes are formed; and defining a coating area which is broader than the effectively optical area, on which the composition including an organic EL material is to be coated. According to this method, a uniform display device without uneven luminance and uneven chrominance within a pixel or among a plurality of pixels in the effectively optical area can be obtained.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an organic electroluminescent(hereinafter abbreviated as “EL”) device and to a fabrication methodtherefor.

[0003] This application is based on Patent Application No. 2000-359885filed in Japan, the contents of which are incorporated herein byreference.

[0004] 2. Background Art

[0005] In recent years, development has accelerated of luminous elementsusing organic substances as a self-luminous display device which mightsupplant conventional liquid crystal display devices. EL elements usingan organic substance as a luminous material can mainly be manufacturedby forming a membrane using vapor deposition of an organic EL material(a luminous material) with low molecular weight as disclosed beginningon page 913 of Appl. Phys. Lett. 51 (12), Sep. 21, 1987, and by coatingan organic EL material with high molecular weight as disclosed beginningon page 37 of Appl. Phys. Lett. 71 (1), Jul. 7, 1997.

[0006] For colorization in the case of a low molecular weight material,respective membranes are formed with various luminous material which arevapor-deposited on respective pixels through covering masks. On theother hand, in the case of a high molecular weight material, it has beennotable to realize colorization by a fine patterning using an ink-jetmethod. Fabrication methods of EL elements using an ink-jet method aredisclosed in JP-H7-235378A1, JP-H10-12377A1, JP-H10-158967A1,JP-H11-40358A1, JP-H11-54270A1, JP-H11-339957A1, and U.S. Pat. No.6,087,196B1.

SUMMARY OF THE INVENTION

[0007] A super fine patterning of an EL material can be realized bymeans of an ink-jet, method because it is possible to eject dropletshaving a diameter of a few micrometers in a high resolution manner andto form a coating therewith. On the other hand, the minute dropletscoated on a substrate tend to dry in an extremely short period, and theydry even faster at edge portions (e.g., upper edge, lower edge, rightedge, and left edge) of the coated area on the substrate where thepartial pressure of the vapor from the minute droplets coated on a pixelarea is relatively low. In addition, in the case in which the ELelements are to be actively driven by TFT (thin-film transistor)elements in use, it may not be allowed to evenly dispose pixels in bothX and Y directions due to the TFT elements and shape and disposition ofelectric wires, and the partial pressure of the vapor may vary locallyaround the droplet coated on each of the pixels. The time difference inthe drying period for the liquid organic material coated on the pixelsthus produced may cause uneven thickness of the organic membrane withina pixel or among a plurality of pixels. The uneven thickness of themembrane, in turn, may cause uneven displaying performance such asuneven luminance, uneven chrominance and so on.

[0008] Based on the above description, an object of the presentinvention is to provide an improved fabrication method for an organic ELdevice that comprises ejecting and coating an organic EL material onelectrodes to form an organic EL layer, with which uniform physicalconditions and drying period for the liquid EL material coated on apixel area can be realized and a uniform organic EL device withoutuneven luminance and uneven chrominance within a pixel or among aplurality of pixels in an effectively optical area can be obtained, andalso to provide such an organic EL device manufactured in accordancetherewith.

[0009] The present invention provides a method for manufacturing an orEL device by coating a composition including an organic EL materialabove a plurality of electrodes to form an organic EL layer above eachof the electrodes. The method comprises: defining an effectively opticalarea in which the plurality of electrodes are formed; and defining acoating area being broader than the effectively optical area, in whichthe composition including an organic EL material is to be coated.

[0010] According to the above fabrication method, uniform physicalconditions near the liquid EL material coated on the effectively opticalarea and uniform drying period for the EL material can be realized inthe effectively optical area, and consequently a uniform thickness ofthe layer within a pixel or among a plurality of pixels an be obtained.An organic EL layer herein referred to includes a variety of layerscontributing to a luminous effect, such as a hole-injection layer, aluminous layer, and an electron-injection layer. An effectively opticalarea herein refers to an area for the display pixels when the organic ELdevice is a display device, and refers to an area contributing tolighting when the organic EL device is a lighting equipment.

[0011] In a method for manufacturing an organic EL device according tothe present invention, the coating area preferably includes theperimeter of the effectively optical area.

[0012] According to this method, the drying period for droplets on thepixels located near edges of the effectively optical area being muchshorter than that for droplets on the pixels located inside theeffectively optical area is avoided; thus, a uniform thickness of thelayer among a plurality of effectively optical pixels can be obtained.

[0013] In another method for manufacturing an organic EL deviceaccording to the present invention, the coating area located along theperimeter of the effectively optical area is preferably a dummy area inwhich the organic EL material solution is also coated to form an organicEL membrane layer.

[0014] Preferably, tie method further comprises: forming a layer made ofthe same material as that of the electrodes in the dummy area; andcoating the composition including an organic EL material on the layer.

[0015] According to the above method, uniform physical conditions nearthe liquid EL material coated on the pixels can be realized even for thepixels located near the edges of the effectively optical area, and thedrying period for droplets on the pixels located near the edges of theeffectively optical area being much shorter than that for droplets onthe pixels located inside the effectively optical area; thus, a uniformthickness of the EL membrane layer among a plurality of pixels can beobtained.

[0016] Another method for manufacturing an organic EL device accordingto the present invention preferably comprises: providing a group ofeffectively optical areas formed of a plurality of the effectivelyoptical areas on a substrate; and defining dummy areas around theeffectively optical areas, respectively and another dummy areaencompassing the group of effectively optical areas.

[0017] A dummy area herein refers to an area relating to neither displaynor lighting. Therefore, the organic EL layer formed in a dummy areadoes not have to be illuminable, but may be slightly illuminable as longas this des not interfere with either display or lighting.

[0018] According to the above method, uniform physical conditions nearthe liquid EL material coated on the pixels located near the edges ofthe effectively optical area can be realized like for other pixels, andthe drying period for droplets on the pixels located near the edges ofthe effectively optical area being much shorter than that for dropletson the pixel located inside the effectively optical area is avoided;thus, a uniform thickness of the EL membrane layer among a plurality ofpixels can be obtained, even when a plurality of the effectively opticalareas are formed on a substrate, each of which is separated from others,in the final manufacturing process, to fabricate a plurality of ELdevices. In this way, a plurality of EL devices without uneven luminanceand uneven chrominance within a pixel or among a plurality of pixels canbe manufactured from a substrate at one time.

[0019] In another method for manufacturing an organic EL deviceaccording to the present invention, a process of coating of thecomposition including an organic EL material is preferably started atthe dummy area prior to coating on the effectively optical area and endsat the dummy area after coating an the effectively optical area.

[0020] According to this method, since the process of coating of theorganic EL material solution is started at the dummy area and ends atthe dummy area, the coating for effectively optical areas in between canbe performed in a stable condition.

[0021] In another method for manufacturing an organic EL deviceaccording to the present invention, individual areas to be coated in theentirety of the coating area are preferably disposed with a constantpitch to each other.

[0022] According to this method, uniform physical conditions near theliquid EL material coated on the effectively optical area and uniformdrying period for the EL material can be realized in the effectivelyoptical area, and consequently a uniform thickness of the EL membranelayer within a pixel or among a plurality of pixels can be obtained.

[0023] In another method for manufacturing an organic EL deviceaccording to the present invention, any one of the electrodes isdisposed relative to adjacent ones of the electrodes at a constantpitch. According to this method, uniform physical conditions near theliquid EL material coated on the effectively optical area and uniformdrying period for the EL material can be realized in the effectivelyoptical area, and consequently, a uniform thickness of the EL membranelayer within a pixel or among a plurality of pixels can be obtained.

[0024] The present invention provides a method for manufacturing anorganic EL device which includes an effectively optical area having aplurality of electrodes and an organic EL layer formed above each of theelectrodes. The method comprises: forming the organic EL layer both onareas to be the effectively optical area and on other areas not to bethe effectively optical area.

[0025] The present invention provides another method for manufacturingan organic EL device which includes an effectively optical area having aplurality of electrodes and an organic EL layer formed above each of theelectrodes. The method comprises: further forming the organic EL layerin areas not having the electrodes and which are supposed to be theeffectively optical area.

[0026] The present invention also provides an organic EL device that ismanufactured by one of the above methods. With such an organic ELdevice, uniform display performance without uneven luminance and unevenchrominance within a pixel or among a plurality of pixels is achieved.

[0027] An organic EL device according to the present inventionpreferably comprises: a plurality of electrodes and an organic EL layerformed above each of the electrodes; an effectively optical area inwhich the electrodes are formed; and a dummy area disposed around theeffectively optical area, in which the electrodes are also formed.

[0028] Preferably, an organic EL device according to the presentinvention further comprises a bank layer disposed between theelectrodes, wherein the organic EL layer in the dummy area is disposedon a layer made of the same material as that of the bank layer.

[0029] In an organic EL device according to the present invention, thebank layer preferably includes an organic bank layer and an inorganicbank layer, and the organic EL layer in the dummy area is disposed on alayer made of the same material as that of the inorganic bank layer.

[0030] In an organic EL device, the bank layer is preferably disposedlaterally between portions of the organic EL layer in the dummy area.

[0031] In an organic EL device according the present invention, theorganic EL layer in the dummy area is preferably disposed on a layermade of the same material as that of the organic bank layer.

[0032] In an organic EL device of the present invention, the organic ELlayer in the dummy area is preferably disposed on a layer made of thesame material as that of the electrodes.

[0033] In an organic EL device of the present invention, the bank layeris preferably formed laterally between portions of the EL layer in thedummy area.

[0034] In an organic EL device according the present invention, adjacentpotions of the organic EL layer are preferably disposed at a constantpitch in both the effectively optical area and the dummy area.

[0035] In an organic EL device according to the present invention, boththe effectively optical area and the dummy area are preferably providedon a substrate, and portions in the effectively optical area on thesubstrate have substantially the same cross-sectional structure as thatof portions in the dummy area on the substrate.

[0036] An organic EL device according to the present invention includesan effectively optical area having a plurality of electrodes and anorganic EL layer formed on each of the electrodes, and the organic ELlayer is formed both on areas supposed to be the effectively opticalarea and on other areas not supposed to be the effectively optical area.

[0037] An organic EL device according to the present includes aneffectively optical area having a plurality of electrodes and an organicEL layer formed above each of the electrodes, and the organic EL layeris also formed in areas not having the electrodes and which are supposedto be the effectively optical area.

[0038] The present invention Archer provides an electronic devicecomprising such an organic EL device as described above. With such anelectronic device, a uniform displaying performance without unevenluminance and uneven chrominance within a pixel or among a plurality ofpixels is achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

[0039]FIG. 1 is a cross section showing an example of a fabricationmethod for an organic EL device using an ink-jet method.

[0040]FIGS. 2A to 2C are cross sections showing an example of afabrication method for an organic EL device using an ink-jet methodrelating to the present invention.

[0041]FIGS. 3A to 8D are process drawings illustrating the firstembodiment of the present invention for manufacturing an organic ELdevice.

[0042]FIGS. 4A and 4B are process drawings illustrating the secondembodiment of the present invention for manufacturing an organic ELdevice.

[0043]FIGS. 5A to 5D are process drawings illustrating the thirdembodiment of the present invention for manufacturing an organic ELdevice.

[0044]FIGS. 6A to 6D are process drawings illustrating the fourthembodiment of the present invention for manufacturing an organic ELdevice.

[0045]FIGS. 7A to 7D are process drawings illustrating the fifthembodiment of the present invention for manufacturing an organic ELdevice.

[0046]FIGS. 8A to 8C are process drawings illustrating the sixthembodiment of the present invention for manufacturing an organic ELdevice.

[0047]FIGS. 9A to 9C are process drawings illustrating the seventhembodiment of the present invention for manufacturing an organic ELdevice.

[0048]FIGS. 10A and 10B schematically show the eighth embodiment of thepresent invention for manufacturing an organic EL device; FIG. 10A is aplan view of a substrate before a hole-injection layer is formed, andFIG. 10B is a partial section view taken along the line M-M′ in FIG.10A.

[0049]FIGS. 11A and 11B are process drawings illustrating the eighthembodiment of the present invention for manufacturing an organic ELdevice.

[0050]FIG. 12 is a plan view of a substrate before a hole-injectionlayer is formed, illustrating the ninth embodiment of the presentinvention for manufacturing an organic EL device.

[0051]FIGS. 13A and 13B are schematic plan views showing the traced pathof an ink-jet head, and illustrate the ninth embodiment of the presentinvention for manufacturing an organic EL device.

[0052]FIG. 14 is a plan view showing another method for manufacturing anorganic EL device similar to that in the ninth embodiment.

[0053]FIGS. 15A to 15C are perspective views of electronic devicesaccording to the tenth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] The preferred embodiments of the present invention will now beexplained with reference to the drawings, wherein organic EL devices arespecifically formed as display devices.

[0055] In a fabrication method for an EL device using an ink-jet method,a hole-injection/transportation layer and a luminous material layer areformed by ejecting a composite ink, produced by dissolving or dispersinga hole-injection layer material and a luminous material of pixel-formingorganic substances in a solvent, from an ink-jet head, to coat thecomposite ink in a pattern on transparent electrodes. In order toaccurately dispose the ejected ink droplets on predetermined areas ofpixels, a partitioning wall (hereinafter referred to as a “bank”) istypically provided to partition the areas of pixels.

[0056]FIG. 1 is a cross sectional view showing an example of a substratestructure that is included in a method for manufacturing an organic ELdevice using an ink-jet method. A circuit element portion 11′ havingthin-film transistors (TFTs) 11 is formed on a glass substrate 10, andtransparent electrodes 12 made of ITO (Indium Tin Oxide) are formed in apattern on the circuit element portion 11′. In addition, SiO₂ banks 13and organic banks 14 consisting of an ink-repelling organic substance oran organic substance made to be ink-repelling are laminated on thesections that separate the transparent electrodes 12 to each other. Theshape of apertures defined by the banks may be, for example, circular,oval, or quadrangular; however, in the case of the quad shape, thecorners thereof preferably have a certain curvature since the compositeink inherently has a surface tension. The material of the organic banks14 may be selected from any materials that comprise excellent heatresistance, liquid-repellency, resistance ink solvents, and adheringcapability to a base substrate. The material for the organic banks 14 isnot necessarily an inherently liquid-repelling material such asfluororesin; it may also be a patterned organic resin such as acrylicresin, polyamide resin, or the like, as is normally used whose surfaceis made liquid-repelling by CF₄ plasma treatment or the like. Althoughthe banks need not be formed by laminating inorganic substances andorganic substances, SiO₂ banks 13 are preferably provided in order toimprove adherence to the transparent electrodes 12 when the transparentelectrodes 12 are, for example, made of ITO. A height of approximately 1to 2 micrometers for the organic banks 14 is sufficient.

[0057] An example of a fabrication method for an EL device that uses anink-jet method will be explained below with reference to FIGS. 2A to 2Cshow each step of the fabrication process.

[0058] As shown in FIG. 2A, a solution including an organic EL materialcomposite ink) is coated in a pattern on a substrate for pixels using anink-jet method to form an organic EL membrane. Composite ink 15 of anorganic EL material is ejected from an ink-jet head 16 and is deputed ina predetermined pattern as shown in FIG. 2B. After coating, the solventin the composite ink is removed by a vacuum treatment and/or heattreatment or flow of nitrogen gas or the like to form organic ELmembrane layers 17, as shown in FIG. 2C. The organic EL membrane layers17 are laminated membranes consisting of, for example, a hole-injectionlayer and a luminous layer.

[0059] In this process, the solvent of the composite ink dries morequickly on the display pixels located near the edges of the effectivelyoptical area, i.e., an area in which pixels relating to display areformed, than on the pixels inside the area since ink droplets are notcoated around the pixels located near the edges of the area and thepartial pressure of the vapor from the ink solvent is lower above thedisplay pixels located near the edges of the area than on the pixelsinside the area, which may cause thickness variations in the membranesamong the display pixels, as shown FIG. 2C.

[0060] In order to uniformly dry droplets coated on each of the pixels,the physical conditions of respective droplets coated on the effectivelyoptical area are preferably set to be uniform by ejecting and depositingthe composite ink around the effectively optical area as well. Morepreferably, the organic material is coated by an ink-jet method over anarea broader than the effectively optical area, whereby a dummy area,i.e., an area in which dummy pixels not relating to display are formed,comprising the same bank structure as display pixels, is defined aroundthe effectively optical area so as to provide physical conditions whichare as uniform as possible for each of the display pixels.

[0061] Individual areas to be coated in the effectively optical area arepreferably disposed at a constant pitch to each other in order toprovide as uniform a drying period for the composite ink as possibleamong the pixels in the effectively optical area. For this purpose, thepixels are preferably disposed at a constant pitch to each other aswell. In the case in which the pitch of the pixels in the X direction isdifferent from that in the Y direction due to disposition of TFTs andbonding wires, ink droplets are preferably ejected in the area betweenthe pixels disposed at a wider pitch so that individual areas to becoated in the entirety of the area for the display pixels are disposedat a constant pitch from each other. More preferably, dummy pixelscomprising the same bank structure as the display pixels are formed inthe area between the pixels disposed at a wider path. The shape of thepixels is not limited to a rotationally symmetric shape such as a circleor a square, and it may also be a rectangle, an oval, or an ellipse.When the pixels having the shape of a rectangle or an oval are disposedat different pitches in the X direction and in the Y direction, asimilar effect can be obtained by providing further areas to be coatedin the area between the pixels disposed at a wider pitch so that theareas to be coated are evenly disposed, although each of the additionalareas to be coated is differently shaped from the display pixels.

[0062] The present invention can be applied not only to a display of anorganic EL device but also to luminous devices and lighting equipmentusing organic EL elements as a light source.

[0063] Although the present invention win be more specifically explainedbelow with reference to several embodiments, the invention is notlimited to these specific embodiments.

[0064] First Embodiment

[0065] The substrate used in the first embodiment is a 2-inch TFTsubstrate in which circular pixels having diameters of 30 μm aredisposed at a pitch of 70.5 μm in both X and Y directions. This TFTsubstrate consists of a glass substrate 25 and a circuit element portion26′ having TFTs 26 formed on the glass substrate. FIG. 3A shows apartial section view (along the X direction) of the right edge portionof the TFT substrate. Transparent electrodes 27 made of ITO are formedon the circuit element portion 26′ and banks consisting of two layersincluding SiO₂ banks 28 and polyimide banks 29 are constructed on thecircuit element portion 26′ so as to divide the transparent electrodes27. The SiO₂ banks 28 are manufactured in a pattern by photo-etchingafter forming a 150 nm thick TEOS (tetraethylorthosilicate) layer by CVD(Chemical Vapor Deposition). The polyimide banks 29, which are 2 μmthick, are formed on the SiO₂ banks 28 through the steps of coating aphotosensitive polyimide an the SiO₂ banks 28, exposure, anddevelopment. The material used to form the banks may be anon-photosensitive substance.

[0066] In FIGS. 3A to 3D, the area in which the transparent electrodes27 are formed is an effectively optical area A and the area in which thetransparent electrodes 27 are not decided by the SiO₂ banks 28 and thepolyimide banks 29 is a dummy area B.

[0067] The polyimide banks 29 are made ink-repelling by atmosphericplasma treatment before applying ink using an ink jet-method. Theatmospheric plasma treatment that is performed under conditionscomprising atmospheric pressure, a power of 300 W, and 1 mm gap betweenthe electrodes and the substrate includes an oxygen plasma treatmentthat is performed under conditions comprising an oxygen gas flow rate of100 ml/m, a helium gas flow rate of 10 l/m, and a table speed of 10 mm/sand a consequent CF₄ plasma treatment that is performed under conditionscomprising a CF₄ flow rate of 100 ml/m, a helium gas flow rate of 10l/m, and a reciprocating table speed of 3 mm/s.

[0068] Composite ink 30, including Baytron™ supplied by Bayer AG as ahole-injection layer material which is dispersed by a polar solventconsisting of isopropyl alcohol, N-methylpyrolidone, and1,3-dimethyl-2-imidazolidinone, is ejected from an ink-jet head (e.g.,model MJ-930C made by Seiko Epson Corporation) for coating at a pitch of70.5 μm in both the X and Y directions. In this coating process, another30 rows of ejection at the same pitch in both lateral and longitudinaldirections around the display pixels is performed. FIG. 3B shows apartial sectional view of the right edge portion of the substrate afterthe composite ink 30 of the hole-injection layer material is coated in apattern. While the composite ink 30 of the hole-injection layer materialis coated on the transparent electrodes 27 in the effectively opticalarea A, the composite ink 30 of the hole-injection layer material iscoated on the polyimide banks 29 in the dummy area B.

[0069] Consequently, the solvent is removed by a treatment at roomtemperature in a vacuum (1 Torr (133.3 Pa)) for 20 minutes, and then ahole-injection layer 31 is formed, as shown in FIG. 3C, by heattreatment at 200° C. (on a hot plate) in nitrogen gas for 20 minutes.The hole-injection layer 31 having a uniform thickness can thus bemanufactured in the effectively optical area A.

[0070] In the next process, three kinds of composite inks, i.e., acomposite ink 32 for a red luminous layer, a composite ink 33 for agreen luminous layer, and a composite ink 34 for a blue luminous layer,are prepared using polyfluorene materials to form luminous layersemitting red, green, and blue light, respectively. Cyclohexylbenzene isused as the ink solvent. As shown in FIG. 3C, the composite inks 32, 33,and 34 are coated in a pattern by ejecting from the ink-jet head at apitch of 211.5 μm in the X direction and at a pitch of 70.5 μm in the Ydirection. In this coating process, another 21 rows of ejection at thesame pitch in both lateral and longitudinal directions in the dummy areaB is performed.

[0071] Then, luminous layers 35, 36, and 37 are formed by heat treatmentat 80° C. on a hot plate in nitrogen gas for 5 minutes. The luminouslayers 35, 36, and 37 having a uniform thickness can thus be formed inthe effectively optical area A.

[0072] After forming the luminous layers, a LiF layer 2 nm thick, a Calayer 20 nm thick, and an Al layer 200 nm thick are respectivelylaminated by a heated vapor deposition in a vacuum so as to form acathode 38, and finally, a layer of epoxy resin 39 is formed forsealing, as shown in FIG. 3D.

[0073] An organic EL device without uneven luminance and unevenchrominance in the area for the display pixels can thus be manufactured.

[0074] Second Embodiment

[0075] In the second embodiment shown in FIGS. 4A and 4B, a TFTsubstrate in which a dummy area B′ is disposed around an effectivelyoptical area A is used, as in the first embodiment. This TFT substrateconsists of a glass substrate 25 and a circuit element portion 26′having TFTs 26 formed on the glass substrate. Transparent electrodes 27made of ITO are formed on the circuit element portion 26 and banksconsisting of two layers including SiO₂ banks 28 and polyimide banks 29are constructed on the circuit layer 26′ so as to divide the transparentelectrodes 27. Thus, display pixels 42 are formed in the effectivelyoptical area A.

[0076] A SiO₂ membrane 28′ extending from the SiO₂ banks is formed inthe dummy area B. The dummy pixels 43 having the same shape as that ofthe display pixels 42 and disposed at the same pitch as that at whichthe display pixels 42 are disposed are defined by polyimide banks 40.FIG. 4A shows a partial cross section of the right edge portion of thesubstrate.

[0077] The same composite ink 41 for the hole-injection layer as in thefirst embodiment is coated in a patter on both the display pixels 42 andthe dummy pixels 43 at a pitch of 70.5 μm, as shown in FIG. 4B. Thehole-injection layers of the display pixels 42 have a uniform thicknessupon completion through the steps of drying and heat treatment as in thefirst embodiment.

[0078] In the next process, composite inks for luminous layersconsisting of polyfluorene materials are coated in a pattern on thedisplay pixels 42 and the dummy pixels 43 as in the first embodiment,the luminous layers have a uniform thickness within the display pixels42 upon completion after drying. The organic EL device has neitheruneven luminance nor uneven chrominance in the effectively optical areaA including the display pixels 42 upon completion through the steps ofcathode forming and sealing.

[0079] Third Embodiment

[0080] In the third embodiment shown in FIGS. 5A to 5D, a TFT substratein which a dummy area B is disposed around an effectively optical areaA, is used, as in the first embodiment. This TFT substrate consists of aglass substrate 25 and a circuit element portion 26′ that TFTs 26′formed on the glass substrate, as shown in FIG. 5A. Transparentelectrodes 27 made of ITO are formed on the circuit element portion 26′and banks consisting of two layers including SiO₂ banks 28 and polyimidebanks 29 are constructed on the circuit element portion 26′ so as todivide the transparent electrodes 27. Thus, display pixels 42 are formedin the effectively optical area A.

[0081] On the circuit element portion 26′ in the dummy area B, dummypixels 44 having the same shape and disposed at the same pitch as thedisplay pixel 42 are defined only by polyimide banks 29. FIG. 5A shows apartial section view of the right edge portion of the substrate.

[0082] The polyimide banks 29 are made to be ink-repelling byatmospheric pressure plasma treatment, as in the first embodiment.

[0083] As shown in FIG. 5B, composite ink 30 including thehole-injection layer material is coated in a pattern on the displaypixels 42 and the dummy pixels 43 at a pitch of 70.5 μm, as in the firstembodiment. While the composite ink 30 of the hole-injection layermaterial is coated on the transparent electrodes 27 in the effectivelyoptical area A, the composite ink 30 of the hole-injection layermaterial is coated on the circuit element portion 26′ in the dummy areaB.

[0084] Consequently, the solvent is removed by a treatment at roomtemperature in a vacuum (1 Torr (133.3 Pa)) for 20 minutes, and then ahole-injection layer 31 is formed, as shown in FIG. 5C, by heattreatment at 200° C. (on a hot plate) in nitrogen gas for 10 minutes.The hole-injection layer 31 having a uniform thickness can thus bemanufactured in the effectively optical area A.

[0085] In the next process, three kinds of composite ink, i.e., acomposite ink 32 for a red luminous layer, a composite ink 33 for agreen luminous layer, and a composite ink 34 for a blue luminous layer,are prepared, and the composite inks 32, 33, and 34 are coated in apattern by ejecting from an ink-jet head at a pitch of 211.5 μm in the Xdirection and at a pitch of 70.5 82 m in the Y direction, respectively,as shown in FIG. 5C. In this coating process, another 21 rows ofejection at the same pitch in both lateral and longitudinal directionsin the dummy area B is preferably performed.

[0086] Then, luminous layers 35, 36, and 37 are formed by heat treatmentat 80° C. on a hot plate in nitrogen gas for 5 minutes. The luminouslayers 35, 36, and 37 having a uniform thickness can thus be formed intie effectively optical area A.

[0087] After forming the luminous layers, a LiF layer 2 nm thick, a Calayer 20 nm thick, and an Al layer 200 nm thick are respectivelylaminated by a heated vapor deposition a vacuum so as to form a cathode38, and finally, a layer of epoxy resin 39 is formed for sealing, asshown in FIG. 5D.

[0088] An organic EL device without uneven luminance and unevenchrominance in the effectively optical area A can thus be manufactured.

[0089] Fourth Embodiment

[0090] In the fourth embodiment shown in FIGS. 6A to 6D, a TFT substratein which a dummy area B is disposed around an effectively optical area Ais used, as in the first embodiment. This TFT substrate consists of aglass substrate 25 and a circuit element portion 26′ having TFTs 26formed on the glass substrate, as shown in FIG. 6A. Transparentelectrodes 27 made of ITO are formed on the circuit element potion 26′0and banks consisting of two layers including SiO₂ banks 28 and polyimidebanks 29 are constructed on the circuit element portion 26′ so as todivide the transparent electrodes 27. Thus, display pixels 42 are formedin the effectively optical area A.

[0091] On the circuit element portion 26′ in the dummy area B, dummypixels 45 having the same shape and disposed at the same pith as thedisplay pixels 42 are formed by laminating the SiO₂ banks 28 and thepolyimide banks 29. FIG. 6A shows a partial section view of the rightedge portion of the substrate.

[0092] Then, as in the first embodiment, the polyimide banks 29 are madeto be ink-repelling by atmospheric pressure plasma treatment andcomposite ink 30 including the hole-injection layer material is coatedin a pattern on the display pixels 42 and the dummy pixels 45, as shownm FIG. 6B. While the composite ink 30 of the hole-injection layermaterial is coated on the transparent electrodes 27 in the effectivelyoptical area A, the composite ink 30 of the hole-injection layermaterial is coated on the circuit element portion 26′ in the dummy areaB.

[0093] Consequently, the solvent is removed under the same condition asin the first embodiment, and then a hole-injection layer 31 is formed,as shown in FIG. 6C, by heat treatment under the same conditions as inthe first embodiment. The hole-injection layer 31 having a uniformthickness can thus be manufactured in the effectively optical area A.

[0094] In the next process, a composite ink 32 for a red luminous layer,a composite ink 33 for a green luminous layer, and a composite ink 34for a blue luminous layer are prepared and each of the composite inks32, 33, and 34 is coated in a pattern by ejecting from an ink-jet, asshown in FIG. 6C. In this coating process, another 21 rows of ejectionat the same pitch in both lateral and longitudinal directions in thedummy area B is performed.

[0095] Then, luminous layers 35, 36, and 37 are formed by heat treatmentat 80° C. on a hot plate in nitrogen gas for 5 minutes. The luminouslayers 35, 36, and 37 having a uniform thickness can thus be formed inthe effectively optical area A.

[0096] After forming the luminous layers, a LiF layer 2 nm thick, a Calayer 20 nm thick, and an Al layer 200 nm thick are respectivelylaminated by heated vapor deposition in a vacuum so as to form a cathode38, and finally, a layer of epoxy resin 39 is formed for sealing, asshown in FIG. 6D.

[0097] An organic EL device without uneven luminance and unevenchrominance in the effectively optical area A can thus be manufactured.

[0098] Fifth Embodiment

[0099] In the fifth embodiment shown in FIGS. 7A to 7D, a TFT substratein which a dummy area B is disposed around an effectively optical area Ais used, as in the first embodiment. This TFT substrate consists of aglass substrate 25 and a circuit element portion 26′ having TFTs 26formed on the glass substrate, as shown in FIG. 7A. Transparentelectrodes 27 made of ITO are formed an the circuit element portion 26′and banks consisting of two layers including SiO₂ banks 28 and polyimidebanks 29 are constructed on the circuit element porton 26′ so as todivide the transparent electrodes 27. Thus, display pixels 42 are formedin the effectively optical area A.

[0100] On the circuit element portion 26′ in the dummy area B, dummypixels 46 having fie same shape and disposed at the same pitch as thedisplay pixels 42 are formed by laminating the SiO₂ banks 28 and thepolyimide banks 29. The TFTs 26 are not provided in the circuit elementportion 26′ in the dummy area B. FIG. 7A shows a partial section view ofthe right edge portion of the substrate.

[0101] Then, as in the first embodiment, the polyimide banks 29 are madeto be ink-repelling by atmospheric pressure plasma treatment andcomposite ink 30 including the hole-injection layer material is coatedin a pattern on the display pixels 42 and the dummy pixels 46, as shownin FIG. 6B. While the composite ink 30 of the hole-injection layermaterial is coated on the transparent electrodes 27 in the effectivelyoptical area A, the composite ink 30 of the hole-injection layermaterial is coated on the circuit element portion 26′ in the dummy areaB.

[0102] Consequently, the solvent is removed under the same conditions asin the first embodiment; then, a hole-injection layer 31 is formed, asshown in FIG. 7C, by heat treatment under the same conditions as in thefirst embodiment. The hole-injection layer 31 having a uniform thicknesscan thus be manufactured in the effectively optical area A.

[0103] In the next process, a composite ink 32 for a red luminous layer,a composite ink 33 for a green luminous layer, and a composite ink 34for a blue luminous layer are prepared and each of the composite inks32, 33, and 34 is coated in a pattern by ejecting from an ink-jet, asshown in FIG, 7C. In this coating process, another 21 rows of ejectionat the same pitch in both lateral and longitudinal directions in thedummy area B is preferably performed.

[0104] Then luminous layers 35, 36, and 37 are formed by heat treatmentat 80° C. on a hot plate in nitrogen gas for 5 minutes. The luminouslayers 35, 36, and 37 having a uniform thickness can thus be formed inthe effectively optical area A.

[0105] After forming the luminous layers, a LiF layer 2 nm thick, a Calayer 20 nm thick, and an Al layer 200 nm thick are respectivelylaminated by a heated vapor deposition in a vacuum so as to form acathode 38, and finally, a layer of epoxy resin 39 is formed forsealing, as shown in FIG. 7D.

[0106] An organic EL device without uneven luminance and unevenchrominance in the effectively optical area A can thus be manufactured.

[0107] The dummy pixels 46 consist of the transparent electrodes 27 andthe SiO₂ banks 28 and the polyimide banks 29 which divide thetransparent electrodes 27. Since the dummy pixels 46 are formedsimilarly to the display pixels 42, except that the TFTs are notincluded, the composite ink 30 of the hole-injection layer materialcoated on the dummy pixels 46 can be dried under the same conditions asfor the display pixels 42. Thus, the hole-injection layer 31 having auniform thickness can be manufactured in the effectively optical area Aand an organic EL device without uneven luminance and uneven chrominancein the area for the display pixels can be obtained.

[0108] Sixth Embodiment

[0109]FIG. 8A shows a part of the area for the display pixels and thearea for the dummy pixels used in the sixth embodiment. FIG. 8A is aplan view of a substrate and TFT elements are not shown in this view.Circular pixels 50 having diameters of 60 μm are disposed at a pitch of80 μm in a lateral (X) direction and at a pitch of 240 μm in alongitudinal (Y) direction. In a longitudinal direction, dummy bankpixels 51 are disposed between the display pixels at a pitch of 30 μm.Another 80 rows of dummy pixels 52 having the same shape as the displaypixels are disposed all around the effectively optical area at a pitchof 80 μm. The display pixels in the embodiment are defined by laminatedbank consisting of SiO₂ banks 53 and polyimide banks 54 as in the aboveembodiments and have similar sectional structure as in the first and thesecond embodiment except for the diameter of the pixels and thedisposing pitch.

[0110] Composite ink 55 for a hole-injection layer as in the firstembodiment is coated in a pattern on the display pixels 50 and the dummypixels 51 and 52 at a pitch of 80 μm, as shown in FIG. 8B. After formingthe hole-injection layer as in the first embodiment, a luminous layer isformed by depositing three kinds of composites 56, 57, and 58 for theluminous layer as in the first embodiment at a pitch of 80 μm in alongitudinal direction and a pitch of 240 μm in a lateral direction andby drying them. The composite inks for the luminous layer are depositedin a pattern, as shown in FIG. 8C. Upon completion of further steps ofcathode forming and sealing, the organic EL device shows neither unevenluminance nor uneven chrominance in the effectively optical area.

[0111] Seventh Embodiment

[0112]FIG. 9A shows a part of the effectively optical area and the dummyarea used in the seventh embodiment. FIG. 9A is a plan view of asubstrate, and TFT elements are not shown in this view. Rectangularpixels 60 which are 50 μm wide and 200 μm long (and having roundedcorners) are disposed at a pitch of 80 μm in a lateral (X) direction andat a pitch of 290 μm in a longitudinal (Y) direction. The gap betweenthe pixels in a lateral direction is 30 μm and the gap between thepixels in a longitudinal direction is 90 μm. Another 30 rows of dummypixels 61 having the same shape as the display pixels are disposed allaround the areas for the display pixels 60 at a pitch of 80 μm and apitch of 290 μm in respective directions. The display pixels 60 aredefined by laminated banks consisting of SiO₂ banks 62 and polyimidebanks 63 as in the above embodiments and have similar sectionalstructure as in the first end the second embodiment, except for the sizeof the pixels and the disposing pitch.

[0113] Composite ink 64 for a hole-injection layer as in the firstembodiment is coated in a pattern on the display pixels 60 and the dummypixels 61 and the composite 64 is further coated in a pattern on themiddle areas between the pixels viewed in a longitudinal direction, asshown in FIG. 9B. Upon completion after drying, the hole-injection layerin the pixels exhibits a uniform thickness. If the composite 64 is notcoated on the middle areas between the pixels viewed in a longitudinaldirection, the thickness of the hole-injection layer would becomeundesirably thick at both ends of the pixels viewed in a longitudinaldirection.

[0114] After forming the hole-injection layer, a luminous layer isformed by depositing three kinds of composites 65, 66, and 67 for theluminous layer as in the first embodiment at a pitch of 240 μm in alongitudinal direction and a pitch of 290 μm in a lateral direction;then, composite inks 65, 66, and 67 for the luminous layer are furthercoated in a pattern on the middle areas between the pixels viewed in alongitudinal direction, as shown in FIG. 9C, as for the hole-injectionlayer. After drying, the luminous layer exhibits a uniform thicknesswithin the pixels and among a plurality of pixels. Upon completionthrough further steps of cathode forming and sealing, the organic ELdevice shows neither uneven luminance nor uneven chrominance in the areafor the display pixels.

[0115] Eighth Embodiment

[0116]FIG. 10A is a plan view of the substrate used in the eighthembodiment. FIG. 10B is a partial cross section taken along the lineM-M′ in FIG. 10A. As shown in FIGS. 10A and 10B, the substrate 101, onwhich a hole-injection layer and a luminous layer have not been formed,consists of a circuit element portion 103 formed on a glass substrate102 and a luminous element portion 104 formed on the circuit elementportion 103. The luminous element portion 104 includes display pixelsand dummy pixels, each of which will be further explained below, and isdefined by an effectively optical area A consisting of the displaypixels and a dummy area B consisting of dummy pixels and disposed aroundthe effectively optical area A.

[0117] The circuit element portion 108 consists of a plurality of TFTelements 105 formed on the glass substrate 102 and first and secondinsulating membranes 106 and 107 covering the TFT elements 105. The TFTelements 106 are disposed in a matrix, to each of which a transparentelectrode 108 made of ITO is connected. The transparent electrodes 108are formed on the second insulating membrane 107 at the positionscorresponding to the TFT elements 105 to be connected. The transparentelectrodes 108 may be formed in the shape of a circle, a rectangle, or arectangle having rounded corners, in a plan view.

[0118] The TFT elements 105 and the transparent electrode 108 are formedonly in the area corresponding to the effectively optical area A in theluminous element portion 104.

[0119] SiO₂ banks 109 and polyimide banks 110 are laminated in theeffectively optical area A in the luminous element portion 104. The SiO₂banks 109 and the polyimide banks 110 are disposed between thetransparent electrode 108 whereby apertures 111 surrounding thetransparent electrode 108 are formed.

[0120] In the dummy area B, the luminous element portion 104 comprises aSiO₂ membrane 109 formed on the second insulating membrane 107 andpolyimide banks 110′ formed on tie SiO₂ membrane 109′. The polyimidebanks 110′ in the dummy area B define dummy pixels 111′ havingsubstantially the same shape as that of the display pixels in theeffectively optical area A.

[0121] With regard to the quantity of the dummy pixels 111′ formed inthe dummy area B, ten or more dummy pixel sets, each of which consistsof three kinds of dummy pixels, i.e., a red, a green, and a blue dummypixel, are preferably disposed in an area of width X′ along thedirection X shown in FIG. 10A. In an area of width Y′ along thedirection Y shown in FIG. 10A, ten or more of dummy pixel rows, each ofwhich consists of a number of dummy pixels, i.e., a number of red,green, and blue dummy pixels, are preferably disposed. More preferably,the dummy pixels are disposed so as to equalize width X′ with width Y′.By this disposition, the drying condition for the composite ink in thepixels near the border of the dummy area B can be made substantially thesame as in the pixels in the middle of the effectively optical area A.In order to make width X′ equal to width Y′, thirty rows of dummy pixelscorresponding to rows of ten dummy pixel sets, each of which consists ofthree kinds of dummy pixels, i.e., a red, a green, and a blue dummypixel, may be formed parallel to the Y direction in the area of widthX′, and ten rows of dummy pixels way be formed parallel to the Xdirection in the area of width Y′, provided, for example. all thepixels, including both display pixels and dummy pixels, are disposed ata pitch of 70.5 μm in the X direction and at a pitch of 211.5 μm in theY direction. In this arrangement, width X′ and width Y′ aresubstantially equalized because the pitch in the Y direction is threetimes that in the X direction. Although the number of the dummy pixelsis not limited, as in the above example, a large number of dummy pixels111′ is not preferable because they may create too wide a peripheralregion not relating to display, and consequently unnecessarily enlargethe display module.

[0122] The polyimide banks 110 and 110′ are made to be ink-repelling byapplying atmospheric pressure plasma treatment to the substrate 101, asin the first embodiment, and then composite ink including ahole-injection layer material is ejected in a pattern from an ink-jethead onto the display pixels 111 and the dummy pixels 111′. Thecomposite ink of a hole-injection layer material is deposited on thetransparent electrode 108 in the display pixels 111 and is deposited onthe SiO₂ membrane 109′ in the dummy pixels 111′.

[0123] A preferred process for ejecting the composite ink including ahole-injection layer material from an ink-jet head comprises, forexample: providing an ink-jet head having nozzles in an array whoselength is substantially the same as the width of the luminous elementportion 104 along a lateral direction (X direction FIG. 10A); andejecting the composite ink while moving the ink-jet head from the bottomin FIG. 10A in the direction of the arrow Y above the substrate 101. Inthis process, the ejection of the composite ink preferably starts in thedummy area B at the bottom of FIG. 10A, proceeds through the effectivelyoptical area A, and ends in the dummy area B at the top of FIG. 10A,i.e., the ejection of the composite irk starts and ends in the dummyarea B. The composite ink in the effectively optical area A driesuniformly because the ejection started in the dummy area B beforeejection in the effectively optical area A.

[0124] Consequently, the solvent is removed under the same condition asin the first embodiment, and then a hole-injection layer 181 is formed,as shown in FIG. 11A, by heat treatment under the same conditions as inthe first embodiment.

[0125] The dummy pixels 111′ are provided around the effectively opticalarea A, to which the steps of ejecting the composite ink and drying asfor the display pixels 111 are also applied. Therefore, the dryingcondition for the display pixels near the border of the dummy area B canbe made substantially the same as for the display pixels in the middleof the effectively optical area A, whereby hole-injection layers 131 ofa uniform thickness can be provided even for the display pixels near theborder of the dummy area B. The hole-injection layers 131 having auniform thickness can thus be manufactured in the entire effectivelyoptical area A.

[0126] In the next process, as in the first embodiment, a composite inkfor a red luminous layer, a composite ink for a green luminous layer,and a composite ink for a blue luminous layer are ejected from anink-head and are deposited on both the display pixels 111 and the dummypixels 111′ in a pattern, and then luminous layers 135, 136, and 137 areformed by heat treatment at 80° C. on a hot plate in nitrogen gas for 5minutes. The luminous layers 135, 136, and 137 having a uniformthickness can thus be formed in the effectively optical area A, like thehole-injection layers 131.

[0127] In this process of forming the luminous layers, the composite inkincluding luminous materials is ejected while moving the ink-jet headfrom the bottom in FIG. 10A in the direction of the arrow Y above thesubstrate 101, as in the process of forming the hole-injection layer,and the ejection of the composite ink preferably starts in the dummyarea B at the bottom of FIG. 10A, proceeds through the effectivelyoptical area A, and ends in the dummy area B at the top of FIG. 10A,i.e., the ejection of the composite ink starts and ends in the dummyarea B. The composite ink including luminous material dries uniformlyover the entirety of the effectively optical area A.

[0128] After forming the luminous layers, a LiF layer 2 nm thick, a Calayer 20 nm thick, and an Al layer 200 μm thick are respectivelylaminated by heated vapor deposition in a vacuum so as to form a cathode138, and finally, a layer of epoxy resin 139 is formed for sealing, asshown in FIG. 11B.

[0129] An organic EL device without uneven luminance and unevenchrominance in the effectively optical area A can thus be manufactured.

[0130] Ninth Embodiment

[0131]FIG. 12 is a plan view of the substrate used in the ninthembodiment. As shown in FIG. 12, the substrate 201 mainly consists of acircuit element portion (not shown) formed on a glass substrate 202 anda plurality of luminous element portions 204 formed on the circuitelement portion. The substrate 201 shown in FIG. 12 includes 16 luminouselement port 204 disposed in a 4-by-4 matrix. Each of the luminouselement portions 204 is provided with display pixels and dummy pixels(not shown) as in the eighth embodiment, and is defined by aneffectively optical area A consisting of the display pixels and a dummyarea B consisting of dummy pixels and disposed around the effectivelyoptical area A.

[0132] The structure of the display pixels in the effectively opticalarea A and of the dummy pixels in the dummy area B are respectively thesame as that of the display pixels 111 and the dummy pixels 111′described in the eighth embodiment. Similarly, the structure of thecircuit element portion (not shown) is the same as that of the circuitelement portion 103 in the eighth embodiment.

[0133] A group C of effectively optical areas consisting of a pluralityof effectively optical areas A is thus formed on the substrate 201.

[0134] The substrate 201 will finally be cut along the dashed linesshown in FIG. 12 and the parts will be separated from each other so asto form 16 small substrates. By using this method, a plurality oforganic EL devices can be manufactured from one substrate at one time.

[0135] On the substrate 201, another dummy area D is provided around thegroup C of effectively optical areas.

[0136] With regard to the quantity of the dummy pixels provided in thedummy area D, ten or more dummy pixel sets, each of which consists ofthree kinds of dummy pixels, i.e., a red, a green, and a blue dummypixel, are preferably disposed in an area of width X′ along thedirection X shown in FIG. 12. In an area of width Y′ along the directionY shown in FIG. 12, ten or more dummy pixel rows, each of which consistsof a number of dummy pixels, i.e., a number of red, green, and bluedummy pixels, are preferably disposed.

[0137] Polyimide banks formed on the substrate 201 is made to beink-repelling as in the eighth embodiment; then, composite ink includinga hole-injection layer material is jected in a pattern from an ink-jethead onto the display pixels and the dummy pixels.

[0138] A preferred process for ejecting the composite ink including ahole-injection layer material from an ink-jet head comprises, forexample providing an ink-jet head having nozzles in an array whoselength is substantially the same as the width of a single luminouselement portion 204 along a lateral direction (X direction in FIG. 12);and ejecting the composite ink while moving the ink-jet head from thebottom in FIG. 12 in the direction of the arrow Y to the top. The widthof the ink-jet head is not limited as in this example, and it may alsobe chosen so as to be a multiple of the width of a single luminouselement portion 204.

[0139] In this process, the traced path of the ink-jet head H may be asshown in FIG. 13A in which the ink-jet head H moves upwardly in view ofFIG. 13A, moves diagonally and downwardly in an idling state, and movesupwardly again, or may be as shown in FIG. 13B in which the ink-jet headH moves upwardly in view of FIG. 13B, moves laterally in an idlingstate, and moves downwardly.

[0140] In both of the ways above, the composite ink is sequentiallyejected onto the dummy areas D and B, the effectively optical area A,the dummy areas B and D, the dummy areas D and B, the effectivelyoptical area A, . . . , and the dummy areas B and D, i.e., the ejectionof the composite ink starts and ends in the dummy area D.

[0141] Alternatively, the process may comprise, as in the eighthembodiment: providing an ink-jet head having nozzles in an array whoselength is substantially the same as the width of the group C ofeffectively optical areas along a lateral direction (X direction in FIG.12); and ejecting the composite ink while moving the ink-jet head fromthe bottom in FIG. 12 in the direction of the arrow Y to the top abovethe luminous element portions 204. In this case, the composite ink issequentially ejected onto the dummy areas D and B, the effectivelyoptical area A, the dummy areas B and D, i.e., the ejection of thecomposite ink starts and ends in the dummy area D.

[0142] In all of the cases described above, the composite ink in theeffectively optical area A dries uniformly because the ejection startedin the area D for the dummy pixels before ejection in the effectivelyoptical area A.

[0143] In the cases shown in FIGS. 13A and 13B in which the ink-jet headtraces a reciprocating path, the ejection of the composite ink in theeffectively optical area A is fairly stable even if the state of the inkcontained in the ink-jet head changes during an idling travel becausethe ejection has started in the area D for the dummy pixels beforeejecting onto the effectively optical area A and the composite ink isalways ejected onto the area D for the dummy pixels after idling of theink-jet head.

[0144] Consequently, the solvent of the composite ink of ahole-injection layer material is removed and a hole-injection layer 131is formed by heat treatment, under the same conditions as in the firstembodiment.

[0145] The dummy pixels included in the dummy area B are provided aroundthe effectively optical area A and these dummy pixels are furthersurrounded by other dummy pixels included in the dummy area D.Therefore, the drying condition for the display pixels near the borderof the dummy area B can be made substantially the same as for thedisplay pixels in the middle of the effectively optical area A, wherebyhole-injection layers of a uniform thickness can be provided in theentirety of the effectively optical area A even for the display pixelsnear the border of the dummy area B.

[0146] The hole-injection layers having a uniform thickness can thus bemanufactured even in a case in which a number of display devices aremanufactured from a single substrate because the dummy area D isprovided around the group C of the effectively optical areas.

[0147] In the next process, as in the first embodiment, a composite inkfor a red luminous layer, a composite ink for a green luminous layer,and a composite ink for a blue luminous layer are ejected from anink-jet head and are deposited in both the effectively optical area andthe dummy area in a pattern, and then the red, green, and blue luminouslayers are formed by heat treatment. The luminous layers having a unitthickness can thus be formed in the effectively optical area A, like thehole-injection layers.

[0148] In this process of forming the luminous layers, the composite inkis preferably ejected while moving the ink-jet head as shown in FIG. 13Aor 13B, as in the process of forming the hole-injection layer, and theejection of the composite ink preferably starts and ends in the dummyarea D, whereby, the composite ink dries uniformly over the entirety ofthe effectively optical area A.

[0149] After forming the luminous layers, a LiF layer 2 nm thick, a Calayer 20 nm thick, and an Al layer 200 nm thick are respectivelylaminated by heated vapor deposition in a vacuum so as to form acathode, and finally, a layer of epoxy resin is formed for sealing.

[0150] An organic EL device without uneven luminance and unevenchrominance in the effectively optical area A can thus be manufactured.

[0151] Although a high molecular material is used for the organic ELlayer in the foregoing embodiments, a low molecular material may be usedinstead. The organic EL layer is preferably formed by a vapor depositionmethod using a mask 71, as shown in FIG. 14, when a low molecularmaterial is used therefor. An organic EL device according to the presentinvention can be manufactured by using a mask having a set of aperturescorresponding to an effectively optical area E and another set ofapertures corresponding to an area other than the effectively opticalarea E, i.e., a dummy area F. Uniform organic EL layers can be formed inthe entirety of the effectively optical area by also providing the dummyarea in the vapor deposition method.

[0152] Tenth Embodiment

[0153] Examples of electronic devices comprising an organic EL devicemanufactured by using a method according to any one of the first toninth embodiments described above will be explained below.

[0154]FIG. 15A is a perspective view of an example of a portabletelephone. In FIG. 15A, reference numeral 600 indicates a body of theportable telephone and reference numeral 601 indicates a display portioncomprising any one of the organic EL devices described above.

[0155]FIG. 15B is a perspective view of an example of a portableinformation processor such as a word processor and a personal computer.In FIG. 15B, reference numeral 700 indicates an information processor,reference numeral 701 indicates an input device such as a keyboard,reference numeral 703 indicates a body of the information processor; andreference numeral 702 indicates a display portion comprising any one ofthe organic EL devices described above.

[0156]FIG. 15C is a perspective view of an example of a watch. In FIG.15C, reference numeral 800 indicates a body of the watch and referencenumeral 801 indicates a display portion comprising any one of theorganic EL devices described above.

[0157] Each of the electronic devices shown in FIGS. 15A to 15C includesa display portion comprising any one of the organic EL devices describedabove and consequently has the same advantages as that of the organic ELdevice manufactured using a method according to any one of the first toninth embodiments described above. Therefore, these electronic deviceswill exhibit an excellent display performance.

[0158] As described above, in a method for manufacturing an organic ELdevice using an ink-jet method for ejecting and coating an organic ELmaterial on a substrate to form an organic EL layer, a dummy coatingarea is provided around an area for display pixels and ink droplets aredisposed at a constant pitch in the area for display pixels, accordingto the present invention, whereby, the organic EL material solutioncoated on the effectively optical area dries uniformly and a uniformdisplay device without uneven luminance and uneven chrominance within apixel or among a plurality of pixels in the effectively optical area canbe obtained.

What is claimed is;
 1. A method for manufacturing an organic EL device,comprising: coating a composition including an organic EL material abovea plurality of electrodes to form an organic EL layer above each of theelectrodes; defining an effectively optical area in which the pluralityof electrodes are formed; and defining a coating area being broader thanthe effectively optical area in which the composition including anorganic EL material is to be coated.
 2. A method according to claim 1,wherein the coating area includes the perimeter of the effectivelyoptical area.
 3. A method according to claim 1, wherein the coating arealocated along the perimeter of the effectively optical area is a dummyarea in which the composition including an organic EL material is alsocoated to form an organic EL layer.
 4. A method according to claim 3further comprising: forming a layer made of the same material as that ofthe electrodes in the dummy area; and coating the composition includingan organic EL material on the layer.
 5. A method according to claim 1further comprising: providing a group of effectively optical areasformed of a plurality of the effectively optical areas an a substrate;and defining dummy areas around the effectively optical areas,respectively, and another dummy area encompassing the group ofeffectively optical areas.
 6. A method according to claim 3, wherein aprocess of coating of the composition, including an organic EL materialis started at the dummy area prior to coating on the effectively opticalarea and ends at the dummy area after coating on the effectively opticalarea.
 7. A method according to claim 1, wherein individual areas to becoated in the entirety of the coating area are disposed at a constantpitch from each other.
 8. A method according to claim 7, wherein any oneof the electrodes is disposed relative to adjacent ones of theelectrodes at a constant pitch.
 9. A method for manufacturing an organicEL device which includes an effectively optical area having a pluralityof electrodes and an organic EL layer formed above each of theelectrodes, the method comprising: forming the organic EL layer both onareas to be the effectively optical area and on other areas not to bethe effectively optical area.
 10. A method for manufacturing an organicEL device which includes an effectively optical area having a pluralityof electrodes and an organic EL layer formed above each of theelectrodes, the method comprising: further forming the organic EL layerin areas not having the electrodes and which are supposed to be theoptically active area.
 11. An organic EL device manufactured using amethod according to claim
 1. 12. An organic EL device having a pluralityof electrodes and an organic EL layer formed above each of theelectrodes comprising: an effectively optical area in which theelectrodes are formed; and a dummy area disposed around the effectivelyoptical area, in which the electrodes are also formed.
 13. An organic ELdevice according to claim 12 further comprising a bank layer disposedbetween the electrodes, wherein the organic EL layer in the dummy areais disposed on a layer made of the same material as that of the banklayer.
 14. An organic EL device according to claim 13, wherein the banklayer includes an organic bank layer and an inorganic bank layer, andthe organic EL layer in the dummy area is disposed on a layer made ofthe same material as that of the inorganic bank layer.
 15. An organic ELdevice according to claim 14, wherein the bank layer is disposedlaterally between portions of the organic EL layer in the dummy area.16. An organic EL device according to claim 13, wherein the organic ELlayer in the dummy area is disposed on a layer made of the same materialas that of the organic bank layer.
 17. An organic EL device according toclaim 12, wherein the organic EL layer in the dummy area is disposed ona layer made of the same material as that of the electrodes.
 18. Anorganic EL device according to claim 17, wherein the bank layer isformed laterally between portions of the organic EL layer in the dummyarea.
 19. An organic EL device according to claim 12, wherein adjacentpotions of the organic EL layer are disposed at a constant pitch in boththe effectively optical area and the dummy area.
 20. An organic ELdevice according to claim 12, wherein both the effectively optical areaand the dummy area are provided on a substrate, and portions in theeffectively optical area on the substrate have substantially the samecross-sectional structure as that of portions in the dummy area on thesubstrate.
 21. An organic EL device including an effectively opticalarea having a plurality of electrodes and an organic EL layer formed oneach of the electrodes, wherein the organic EL layer is formed both onareas supposed to be the effectively optical area and on other areas notsupposed to be the effectively optical area.
 22. An organic EL deviceincluding an effectively optical area having a plurality of electrodesand an organic EL layer formed above each of the electrodes, wherein theorganic EL layer is also formed in areas not having the electrodes andwhich are supposed to be the effectively optical area.
 23. An electronicdevice comprising an organic EL device according to any one of claims12, 21, and 22.